A typical working vehicle such as a wheel loader is provided with working equipment including a bucket. When seen in a cross sectional view, a known bucket includes: a middle portion curved in an arc with a predetermined bucket radius; a bottom linearly extending from a lower side of the middle portion in a tangent direction of the arc; and a top linearly extending from an upper side of the middle portion in the tangent direction of the arc (see, for instance, Patent Literature 1).